|
|
||||||||
Laboratoire de Plasticité Neuromusculaire, Université des Sciences et Technologies de Lille 1, F-59655 Villeneuve d'Ascq Cedex, France
We examined the changes in functional properties of triceps brachii skinned fibers from monkeys flown aboard the BION 11 satellite for 14 days and after ground-based arm immobilization. The composition of myosin heavy chain (MHC) isoforms allowed the identification of pure fibers containing type I (slow) or type IIa (fast) MHC isoforms or hybrid fibers coexpressing predominantly slow (hybrid slow; HS) or fast (hybrid fast) MHC isoforms. The ratio of HS fibers to the whole slow population was higher after flight (28%) than in the control population (7%), and the number of fast fibers was increased (up to 86% in flight vs. 12% in control). Diameters and maximal tensions of slow fibers were decreased after flight. The tension-pCa curves of slow and fast fibers were modified, with a decrease in pCa threshold and an increase in steepness. The proper effect of microgravity was distinguishable from that of immobilization, which induced less marked slow-to-fast transitions (only 59% of fast fibers) and changed the tension-pCa relationships.
skinned fibers; atrophy; contractile proteins; myosin heavy chain; calcium affinity
This article has been cited by other articles:
![]() |
A. Higashibata, N. J. Szewczyk, C. A. Conley, M. Imamizo-Sato, A. Higashitani, and N. Ishioka Decreased expression of myogenic transcription factors and myosin heavy chains in Caenorhabditis elegans muscles developed during spaceflight J. Exp. Biol., August 15, 2006; 209(16): 3209 - 3218. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. R. Adams, V. J. Caiozzo, and K. M. Baldwin Skeletal muscle unweighting: spaceflight and ground-based models J Appl Physiol, December 1, 2003; 95(6): 2185 - 2201. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Harrison, D. L. Allen, B. Girten, L. S. Stodieck, P. J. Kostenuik, T. A. Bateman, S. Morony, D. Lacey, and L. A. Leinwand Skeletal muscle adaptations to microgravity exposure in the mouse J Appl Physiol, December 1, 2003; 95(6): 2462 - 2470. [Abstract] [Full Text] |
||||
![]() |
I. Endo, D. Inoue, T. Mitsui, Y. Umaki, M. Akaike, T. Yoshizawa, S. Kato, and T. Matsumoto Deletion of Vitamin D Receptor Gene in Mice Results in Abnormal Skeletal Muscle Development with Deregulated Expression of Myoregulatory Transcription Factors Endocrinology, December 1, 2003; 144(12): 5138 - 5144. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Stevens, C. Bozzo, T. Nemirovskaya, V. Montel, M. Falempin, and Y. Mounier Contractile properties of rat single muscle fibers and myosin and troponin isoform expression after hypergravity J Appl Physiol, June 1, 2003; 94(6): 2398 - 2405. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |